Heretofore, it has been accepted commercial practice to attach punch and die assemblies to punch and die shoes of a die set adapted to be assembled out of a press and then positioned between the ram and bed or bolster of the press. Accurate positioning of the tip of a punch, which is associated with a punch assembly, relative to a punch tip receiving opening of a die member, which is associated with a die assembly, is effected by providing a guide member for the punch tip and positioning such guide member and the die member within aligned locating openings defined by punch and die templets, which are in turn maintained in accurate alignment during punching operations by guide assemblies associated with the die set. Reference may be had to U.S. Pat. No. 4,104,941 for a more complete description of a die set of this construction.
It has also been proposed to provide punch and die sets of the general type described above, wherein one or both of the punch and die shoes are eliminated from the die set, whereby to greatly reduce the overall weight thereof, and in this connection reference may be made to U.S. Pat. Nos. 2,296,136; 2,373,962; 2,395,083 and 2,553,615. Also, in U.S. Pat. No. 2,296,136 use appears to be made of guide and die members of like construction adapted to be threadably connected to adjacent parts of the punch and die assemblies. However, it does not appear that these systems have met with commercial acceptance.
It is also known to form a punch from multiple parts including a punch driver and a punch element, which are removably coupled as by forming the parts with a screw threaded coupling or by providing a separate clamping nut to clamp an enlarged head of the punch element against a threaded end of the punch driver, as in U.S. Pat. No. 856,110.